This invention relates to equipment which involves the handling of liquids such as a printing apparatus of the type employing an ink fountain assembly. In such an apparatus, the ink fountain is provided for containing ink, and a roller and metering blade associated with the ink fountain serve to meter the ink to the apparatus in the course of a printing operation.
The following description will be confined to a discussion of a printing apparatus of the aforesaid type in order to illustrate the practice of the invention. It will be understood, however, that the invention is applicable to other equipment which handles liquid, such as coating equipment, and which employs a removable metering means whereby sealing against leakage can become a problem. This would be particularly true where the liquid being handled has a viscosity higher than water.
Concerning the printing application of the invention, it has been recognized that problems develop with ink fountain assemblies due to leakage of printing ink. Thus, ink will drip from the ink fountain onto various parts of a printing apparatus such as a receiving tray and chain delivery means. In addition, ink migration into journal bearings can cause machine malfunction if the ink is allowed to dry. Leakage of ink, therefore, creates definite problems from the standpoint of clean-up and other maintenance and, in addition, ink is wasted whenever such leakage takes place.
Leakage problems have been addressed in U.S. patents to Bechman, U.S. Pat. No. 1,142,659; Swaim, U.S. Pat. No. 1,469,544; Andersson, U.S. Pat. No. 2,218,945; Mueller, U.S. Pat. No. 2,887,049 and Dutro, et al. U.S. Pat. No. 3,135,197. These patentees essentially disclose various proposals for sealing means designed to reduce or eliminate the leakage problem. It has been applicant's experience, however, that such prior art teachings have been ineffective for the intended purposes.